Iron-catalyzed cross-dehydrogenative coupling esterification of unactive C(sp3)-H bonds with carboxylic acids for the synthesis of α-acyloxy ethers.

Jincan Zhao, Hong Fang, Wei Zhou, Jianlin Han, Yi Pan

Index: J. Org. Chem. 79(9) , 3847-55, (2014)

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Abstract

An iron-catalyzed oxidative esterification reaction between unactivated C(sp(3))-H bonds from symmetric and asymmetric ethers and carboxylic acids using di-tert-butyl peroxide (DTBP) as the oxidant via a cross dehydrogenative coupling (CDC) reaction was established, which tolerates a wide range of cyclic ether substrates to react with aromatic acids and phenylacetic acid, providing an efficient method for the preparation of α-acyloxy ethers with good to excellent yields. Intermolecular competing kinetic isotope effect (KIE) experiments were also carried out, which indicate that C(sp(3))-H bond cleavage may be the rate-determining step of this CDC reaction.